Waste to energy could address twin whammy of energy and green crises
SA has a power deficit of about 21,000MW because of demand exceeding available supply. The gap is widening and compounded by dilapidated infrastructure, lack of capital investment and mismanagement.
The Council for Scientific & Industrial Research (CSIR) estimated that the economy costs of electricity disruption in 2019 were at least R59bn.
All possible creative and innovative energy solutions must be explored, taking the opportunity to diversify the energy mix and reduce the reliance on coal-powered generation. The role of renewable energy solutions must particularly be redefined, and evaluation extended beyond nuclear, wind and solar.
Especially the generation of energy from waste, could be a double-edged sword that addresses the energy crisis and the environmental challenge posed by waste.
Waste to energy refers to treatment technologies that convert waste to electricity, heat, fuel, or other usable forms of energy. Solid waste is burnt to produce steam in a boiler that is used to generate electricity. According to the World Bank, the world’s cities generated 2.01-billion tonnes of solid waste in 2016 and this is expected to grow 70% to 3.4-billion tonnes by 2050.
The SA Waste Information Centre says the country has more than 860 landfills. In 2020 these had 48.5-million tonnes of waste (64% hazardous and 36% general waste), of which 34% was recycled. These landfills pose a health risk through the emission of greenhouse gases, which cause climate change and respiratory diseases. They also contaminate the soil near the dump sites.
Thermal waste to energy can be a possible solution to reduce the volume of waste entering landfills by 75%-90%, while complementing existing energy solutions in addressing SA’s power deficit.
SA has only one large-scale waste-to-energy plant, at New Horizon Energy, Athlone, in the Western Cape. It processes 500-600 tonnes of general waste a day. The plant was launched in 2017 at an investment of R400m. This contrasts with other emerging market economies similar to SA that are intensifying their waste-toenergy initiatives. The case of Malaysia is instructive.
SIX NEW PLANTS
The Malaysian government commissioned the country’s first waste-to-energy plant in 2009. It aims to build six new plants near big cities, including Sungai Udang and Bukit Payung, by the end of the year. The Kajang waste-to-energy plant about 20km from the capital, Kuala Lumpur, has the capacity to process about 1,100 tonnes of municipal solid waste daily, generating about 8MW of electricity a day, enough to supply 5,200 average households.
The electricity that is produced powers the waste-toenergy facility, and the remainder is sold to the national power grid through net metering. The local authorities in the Kajang municipality contracted to deliver 700 tonnes of unsegregated municipal solid waste daily and are charged a tipping fee per tonne. The waste is preprocessed to enable recovery of recyclables such as plastics and metals and segregation of wet waste to enhance power generation, thus maximising the extraction of energy from the waste and contributing to a circular economy.
Embarking on this journey requires concrete steps be taken now. SA must understand the type of waste that is being disposed of. The UN says organic waste makes up 53%56% of municipal solid waste in low- and medium-income countries. This suggests the quality of waste in SA is likely to be low (from an energy-generation potential perspective) due to its high moisture content. The type of waste will influence the viability and effectiveness of waste to energy as an alternative source of power.
Lessons can be learnt from countries such as Brazil, which produces 51% organic waste. In 2018 a biomethanisation unit was set up in Rio de Janeiro aimed at transforming organic matter from municipal solid waste into biogas, used for the generation of energy and biofuel. The organic waste is also transformed into organic compost and used as fertiliser.
The plant processes 35-50 tonnes of waste a day, creating energy to power plant operations and the company’s fleet of 19 electric vehicles.
A legislative framework that includes strategies for maintenance, monitoring and evaluation of the waste-to-energy facilities must also be created. This can include guidelines on safe disposal of toxic byproducts since thermal waste to energy can be a dangerous source of emissions if it is mismanaged. Legislation should be in line with internationally recognised emission standards, monitoring and enforcements to avoid contradictory laws.
For example, the Philippines lifted the thermal waste-toenergy ban in 2016 but it contradicts the country’s Clean Air Act.
Discussions must furthermore be had regarding investment requirements, finance sources and operating models. This is important given the country’s current debt levels and competing priorities, including containing the Covid-19 pandemic.
Waste to energy is an option worth considering to avert both the energy and waste crisis the country is facing. The electricity supply and demand gap can be narrowed by using the existing waste through thermal waste-to-energy plants or through biogas.
The success and progress made by other countries within the same emerging market context as SA inspire confidence that similar solutions can make a difference locally.